Electrical connecter



Dec. 30, 1930. w, H BROER 1,786,598

ELECTRICAL CONNEGTER Filed Sept. 3, 1929 Patented Dec. 30, 1930 UNITED s'rATes messes WILLIAM H. BROEB, OF YANK'ION, SOUTH DAKOTA ELECTRICAL CONNECTER Application filed September 3, 1929. Serial No. 389,983.

My invention relates to electrical connecters of the plug and socket type and has for its object to provide a connecter of this type which is so constructed that it will be impossible'for a person to receive a shockfrom contact with either the interior of the socket or with the plug.

A furtherobject is to provide a device of this character in which it will be impossible In for an electrical circuit, of which the electrical connecter forms a part, to become cir cuited by the insertion of a foreign object into the socket.

My invention is particularly adaptable to 15, a connecter of the wall plug type adapted to be used primarily in homes where a person unfamiliar with the electrical devices should be protected against injury from such electrical devices.

My invention is carried out primarily by the provision of a socket provided with a pair of openings or recesses in which are mounted the two electrical contacts of the socket, the extremities of the contacts being removed from the inner surface of the plug sufficiently so that they cannot be contacted with by any foreign object insertedinto the socket.

My invention is carried out further by employment of the plug having a pair of contact points adapted to register with the'contact points of the socket and means for spreading the plug contact points into engagement with the contact points of the socket.

Another object of my invention is to combine with the safety features of the plug the A feature of easy operation, the parts being ar-,

ranged so that the plug contacts will be spread automatically by the pushing of the plug-into the socket and will beretracted by 4.0 pulling the plug from the socket.

' Other objects of my invention are to provide a connecter of this character which is of simple, durable and inexpensive construction and which may be readily disassembled for the purpose of repair, inspection and the like.

' With these and other objects in view, my invention consists in the construction, ar rangement and combinationof the various parts of ny device, whereby the'objects con templated are attained, asvhereinafter more tact points 16.

fully set forth, pointed out in my claims, and illustrated in the accompanying drawings, in which: I u

Fig. 1 is a sectional view through a portion of a wall to which my invention is at tached, the connecter being shown in elevation.

Fig. 2 is a disassembled, sectional view taken longitudinally through the connecter.

Fig. 3 is a sectional view taken longitudi nally through the connecter with the parts in, connected position.

Fig. l is a detail view of one of the contact points and its resilient mounting.

Fig. 5 is a plan view of the connecter with the plug partially removed from the socket.

Fig. 6 is a front elevation of the face plate! I have used the reference character 10 to indicate generally a wall of a dwelling house or the like, which is provided with an opening 11 to receive the socket of an electrical con-.

necter.

The socket of my invention is formed in a conventional manner of insulating material including the socket portion proper 12 and 7 the flange 13, which is provided with openings 14: to receive screws or the like 15, by means of which the socket is secured in the opening 11.

The wall of the socket is provided with a pair of opposed openings 16, in which are received the contact points 17 in the socket. It will be noted, by reference to Fig. 2, that the normal position of the contact points 17 is such that their inner extremities are removed from the inner surface of the socket, whereby it will be impossible for a foreign object in serted in the socket to come into contact with the contact points 17.

The contact points 17. are supported in their positions shown in Fig. 2 by a pair of fiat springs 18, which are soldered or welded to the contact points. The springs 18 are secured to the socket 12 as at 19. V

The springs 18 may be employed to carry current to the contact points 17 or the current carrying wires 20 may be connected directly to the contact points 17 by means of binding post screws 21, threaded. directly into the con- The plug comprises two relatively movable members.

The longitudinal opening through the sleeve A is adapted to snugly receive the shaft B and yet to allow the shaft B to slide easily through the sleeve.

The shaft B is provided with a longitudinal slot 22, which receives a pin 23, secured in the socket A. The function of the pin 23 is to limit movement of the shaft when it is being pulled out of the sleeve so that the sleeve will be pulled out of the socket together with the shaft.

The sleeve A is provided with a pair of contact points 24, which are mounted in openings 25 in the sleeve and which are carried by a pair of flat spring arms 26, secured at 27 to the sleeve. The shaft, when pushed into the sleeve, will spread the arms 26, pushing the contact points 24 away from each other.

In order to facilitate this action, the shaft B is pointed as at 28.

The socket 12 is provided with an end wall 29, which only partially closes the socket so that refuse and foreign matter may not fill the socket. The function of the wall 29 is to act as a stop against which the sleeve A may contact. The openings 16 and 25 are so arranged that when the sleeve A contacts with the wall 29, the openings 25 and 16 will register with each other.

The shaft B is provided with a pair of metal strips 30, of conducting material, which serves to establish contact with the contact points 24 when the shaft is pushed into the sleeve. The contact strips 30 are provided with binding posts 31 to which may be attached a pair of conducting wires.

A handle for the shaft B is formed of a pair of handle members 32, recessed to receive the shaft and to receive the conducting wires ust mentioned. The two halves of the handle are held together by means of a screw 33 and the shaft is thereby locked between the handle members.

In the practical operation of the device, when the sleeve A is inserted in the socket 12 and the handle pushed inwardly, the sleeve will face contact with the wall 29 and further pressure upon the handle will then move the shaft B inwardly, spreading the contact points 24 until the latter enter the openings 16 and contact with the contact points 17. \Vhen the plug is to be withdrawn from the socket, the handle will be simply pulled outwardly, the shaft being first retracted from the sleeve to allow the contact points 24 to spring inwardly and as the pin 23 reaches the end of the slot 22, the sleeve A being drawn from the socket together with the handle.

The advantages of the device have already been stated but may be repeated here in conclusion. It quite often happens that achild will insert its finger in a wall plug socket and be seriously burned by establishing a connection between the contact points of a socket. This is impossible in my device, where the contact points are removed from the inner surface of the socket.

In the same way, it is impossible for a for eign object such as a knife or a coin to be inserted in the socket in such a manner as to short circuit the contact points. It will be understood in this connection that ordinarily the socket is connected to the supply wires of a power circuit while the plug carries the wires which are to be attached to the electrical appliance to be energized. Shorting of the contact points of a wall socket is apt to burn the insulation from the wires if it does not blow the power fuse first.

The device is very simple and inexpensive in construction, the shaft B being readily removed from the sleeve A by removing the pin 23 and the binding posts 31 being accessible by removing the screw 33 and the handle elements 32. The binding posts 21 of the socket are very accessible for the attachment of the wiring and are fully protected by their position relative to the socket normally received in a wall opening 11.

It will be understood that my invention may be embodied in a connecter such as that employed in an extension cord and in this case the socket will be provided with a shell or casing to enclose the contact points 17 from the outside. Since insulating casings for connecters are old and any suitable insulating cover might be employed for this purpose, I'have not illustrated the same in the drawings. It will be understood that my invention relates to the protection of the contact points from the inside of the socket so that it will be impossible to make contacts with them on the inside of the socket where the plug must have access to them.

Some changes may be made in the construction and arrangement of the parts of my invention without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims, any modified forms of structure or use of mechanical equivalents, which may be reasonably included within their scope.

I claim as my invention:

1. In a safety electrical plug connecter, a socket, provided with a pair of opposed openings, a pair of contact points mounted in said openings, in positions removed from the inner surface of the socket, re silient means supporting the contact points in said positions and allowing them to recede from said'positions, a plug comprising a shaft, a handle on the shaft, a sleeve longitudinally slidable on the shaft. receivable in the socket, and provided with a pair of opposed openings adapted to register with the socket openings, a pair of contact points mounted in said openings, resilient means supporting the contact points, and current carrying devices on the shaft connected with the contact points of the sleeve, the shaft being provided with means to spread said last mentioned contact points while moving longitudinally in the sleeve.

2. In a safety electrical plug connecter, a socket, provided with a pair of opposed openings, a pair of contact points mounted in said openings, in positions removed from the inner surface of the socket, resilient means supporting the contact points in said positions and allowing them to recede from said positions, a plug comprising a shaft, a handle on the shaft, a sleeve longitudinally slidable on the shaft, receivable in the socket, and provided with a pair of opposed openings adapted to register with the socket openings, a pair of contact points mounted in said openings, resilient means supporting the contact points, current carrying devices on the shaft connected with the contact points of the sleeve, the shaft being provided with means to spread said last mentioned contact points while moving longitudinally in the sleeve, and means to limit movement of the plug sleeve into'the socket.

3. In a safety electrical plug connecter, a socket, provided with a pair of opposed openings, a pair of contact points mounted in said openings, in positions removed from the inner surface of the socket, resilient means supporting the contact points in said positions and allowing them to recede from said positions, a plug comprising a pair of relatively removable members, one of which is adapted to be received in the socket, and apair of contact points adapted to be spread apart by relative movement of the other, to enter the socket openings, and to engage the socket contact points. 7

4. In a safety electrical plug connecter, a socket, provided with a pair of opposed openings, a pair of contact points mounted in said openings, in positions removed from the inner surface of the socket, resilient means supporting the contact points in said positions and allowing them to recede from said positions, a plug comprising a shaft, a handle on the shaft, a sleeve longitudinally slidable on the shaft, receivable in the socket, and provided with a pair of opposed openings adapted to register with the socket openings, a pair of contact points mounted in said openings, resilient means supporting the contact points, and current carrying strips on the shaft, slidingly contacting with the contact points of the sleeve, the shaftbeing pointed to spread the contact points of the sleeve.

5. In a safety electrical plug connecter, a socket, provided with a pair of opposed openings, a pair of contact points mounted in said openings, in positions removed from the inner surface of the socket, resilient means supporting the contact points in said positions and allowing them to recede from said positions, a plug comprising a shaft, a handle on the shaft, a sleeve longitudinally slidable on the shaft, receivable in the socket, and provided with a pair of opposed openings adapted to register with the socket openings, a pair of contact points mounted in said openings, resilient means supporting the contact points, current carrying devices on the shaft connected with the contact points of the sleeve, the shaft being provided with means to spread said last mentioned contact points while moving longitudinally in the sleeve, means to limit the movement of the plug sleeve into the socket, and means connecting the sleeve and shaft to allow only limited, relative sliding movement thereof.

6. In a safety electrical plug connecter, a socket, provided with a pair of opposed openings, a pair of contact points mounted in said openings, in positions removed from the inner surface of the socket, resilient means supporting the contact points in said positions and allowing them to recede from said positions, a plug comprising a shaft, a handle onthe shaft, a sleeve longitudinally slidable on the shaft, receivable in the socket, and provided with a pair of opposed openings adapted to register with the socket openings, a pair of contact points mounted in said open ings, resilient means supporting the contact points, and current carrying devices on the shaft connected with the contact points of the sleeve, the shaft being pointed to spread the contact points of the sleeve.

Signed this 20th day of August, 1929, in the county of Woodbury and State of Iowa.

WVILLIAM H. BROER. 

